High Poly to Low poly normal bake looks weird
Here is a simple workflow of mine:
make a retopo and be sure they are not flipped and you have a good UV layout with no overlap:

make it a little bit fat with Displace modifier (anything you do a retopo on would be a bit slimmer by nature of retopo)

adjust your options to YOUR scale (I always work in real world scale because it's important for my assets to have correct scale)

now you should have a flawless bake of your normals.
There are some part that can be a little problematic like this part here:

for those, instead of going mad with ray cast, do a cage.
A cage is a mesh (same as low poly) that helps rays to be cast correctly.
you should just sink the low poly in it and adjust the problematic areas carefully. Here is how a cage works:

red marks are your default rays distance. They work correct for the areas that low poly is sinking inside your high poly but in a place close together like the foot (RED MARK 1) here the rays will intersect each other so if orange is low poly and black is high, blue is our cage and green is our new guided rays.
as you can see cage (blue) should 100% sink the orange and black (low and high poly) for corrected rays (green) to work correctly.
By the end of this, your bake should be flawless.